Patriots relying on pass-rush boost from Adrian Clayborn, Derek Rivers

In the lead-up to New England Patriots training camp, with the first public practice scheduled for July 26, it is timely to review each position on the roster with our annual "roster locks" series. After previously highlighting the running backs and wide receivers, let's move on to the defensive ends:

Locks: Trey Flowers, Adrian Clayborn, Deatrich Wise Jr., Derek Rivers

On the bubble: Geneo Grissom, Eric Lee

Long shot: Keionta Davis, Trent Harris

Explaining the locks: Flowers, who led the Patriots with 6.5 sacks last season, enters the final year of his rookie contract. He is the No. 1 option on the depth chart, followed by the 30-year-old Clayborn, who was the team's highest-priced free-agent signing with a two-year deal that has a base value of $10 million. Clayborn, who mostly plays the right side, should help provide a boost to the team's pass rush and made an impression in spring practices with his commitment to his craft. Wise was the team's most productive rookie last season, playing more than anticipated (51 percent of the snaps), most often in obvious passing situations in a rush-type role. He'll look to expand that role in 2018, with good health an obvious key after he sustained two documented concussions last year. Rivers, the team's top draft pick from 2017 (third round, No. 83), is coming back from a torn ACL from last August that sidelined him all year. He set Youngstown State's record for career sacks.

Roster management: When the Patriots won Super Bowl LI two seasons ago, they successfully implemented a four-man rotation at defensive end with Chris Long, Rob Ninkovich, Jabaal Sheard and Flowers. That reflects how they'd like to go four-deep at the position, so they don't run into a similar situation as last year when they were short at the position because of a combination of injuries (Rivers) and personnel hiccups (Kony Ealy), which led them to sign Lee off Buffalo's practice squad and sign veteran James Harrison late in the year. Grissom, a 2015 third-round pick, is a depth option whose primary contributions have come on special teams. Davis is an intriguing longshot after spending last season on the team's reserve/non-football injury list, as he was a disruptive pass-rusher at Tennessee-Chattanooga (24 sacks in his final two seasons). Harris is an undrafted free agent from the University of Miami who has rushed the passer in both 3-4 and 4-3 schemes.

Stat of note: Flowers had played just four snaps his entire 2015 rookie season before emerging as a key cog the past two years by playing 54 and 75.6 percent of the defensive snaps. That serves as a reminder of how players who weren't truly on the radar one year can emerge to seize a notable role in ensuing years.

One thing to watch for in camp: One-on-one pass-rush drills in full pads are usually held in the far corner of the practice field, so those in attendance would benefit from bringing a pair of binoculars. Those drills, with offensive line coach Dante Scarnecchia calling out the snap count as the defensive linemen work against offensive linemen, show which players are getting off the ball with the most explosion.